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From: Dai Ngo <dai.ngo@oracle.com>
To: chuck.lever@oracle.com, jlayton@kernel.org
Cc: linux-nfs@vger.kernel.org
Subject: [PATCH v2 1/1] NFSD: send OP_CB_RECALL_ANY to clients when number of delegations reaches its limit
Date: Sun,  3 Mar 2024 14:23:02 -0800
Message-Id: <1709504582-8311-1-git-send-email-dai.ngo@oracle.com>
Precedence: bulk

The NFS server should ask clients to voluntarily return unused
delegations when the number of granted delegations reaches the
max_delegations. This is so that the server can continue to
grant delegations for new requests.

Signed-off-by: Dai Ngo <dai.ngo@oracle.com>
---
 fs/nfsd/nfs4state.c | 3 +++
 1 file changed, 3 insertions(+)

v2: move declaration of deleg_reaper() up to other forward
    declarations in the file.

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index fdc95bfbfbb6..961000261b3e 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -87,6 +87,7 @@ static void nfs4_free_ol_stateid(struct nfs4_stid *stid);
 void nfsd4_end_grace(struct nfsd_net *nn);
 static void _free_cpntf_state_locked(struct nfsd_net *nn, struct nfs4_cpntf_state *cps);
 static void nfsd4_file_hash_remove(struct nfs4_file *fi);
+static void deleg_reaper(struct nfsd_net *nn);
 
 /* Locking: */
 
@@ -6550,6 +6551,8 @@ nfs4_laundromat(struct nfsd_net *nn)
 	/* service the server-to-server copy delayed unmount list */
 	nfsd4_ssc_expire_umount(nn);
 #endif
+	if (atomic_long_read(&num_delegations) >= max_delegations)
+		deleg_reaper(nn);
 out:
 	return max_t(time64_t, lt.new_timeo, NFSD_LAUNDROMAT_MINTIMEOUT);
 }
-- 
2.39.3